Such an electronic ballast for a lamp is known. In this case, the difference between the DC voltage level of the first connection for the lamp and of the second connection for the lamp is determined and evaluated in a signal evaluation unit which is connected to the ground potential as the reference potential in order to provide information on the remaining life of the lamp. In particular, when it is established that the lamp is approaching its end of life (EoL), driving of the bridge circuit is disconnected in order to prevent damage in the electronic ballast. A DC voltage at the level of the DC voltage potential of the center point of the bridge circuit is superimposed on the actual DC voltage useful signal. Since the voltage dividers and comparator circuits required for evaluation purposes are subject to the conventional tolerances, this means that typically +/−4% of the potential at the center point of the bridge circuit is produced as the error in the measured value by a voltage divider when using resistors with a 1% tolerance. The supply voltage is, for example, 450 V; the potential at the center point of the bridge circuit is therefore approximately 225 V. With an error of +/−4%, the error in the measured value is thus approximately +/−9 V. Since the DC voltage useful signal for identifying an “EoL situation” is generally of the order of magnitude of from 10 to 20 V, reliable EoL detection is therefore not possible.